1. Field of the Invention
Aspects of the present invention relate to a recording medium, a method and apparatus for reproducing data on the recording medium, and a method and apparatus for recording data on the recording medium.
2. Description of the Related Art
New high density recording media have been developed recently and allow large amounts of high quality video and audio data to be recorded and stored thereon. Examples of such high density recording media include Blu-ray discs (BD), high definition digital versatile discs (HD-DVD), and disks with even higher recording densities than those of BDs and HD-DVDs.
The above high density recording media are based on a next-generation recording medium technology. Specifically, the high density recording media are next-generation optical recording solutions that can store amounts of data far exceeding those of conventional recording media (such as DVDs). Furthermore, the development of such high density recording media has recently been carried out together with other digital devices.
FIG. 1 is a diagram illustrating a structure of a recording area of a high density optical recording medium. Referring to FIG. 1, the optical recording medium is divided into 3 parts: a lead-in area, a data area and a lead-out area. In particular, the data area includes a user data area, in which actual user data is recorded, and a spare area to replace a defective area in the user data area. The spare area includes an inner spare area (ISA) located in an inner portion of the data area, and an outer spare area (OSA) located in an outer portion of the data area.
In the optical recording medium structure as illustrated in FIG. 1, data is recorded in units of clusters in all areas of the data area. In particular, each cluster is divided into a plurality of recording units. For example, in the present disclosure, the recording unit is referred to as a sector, each cluster includes a total of 32 sectors, and one address unit number (AUN) is assigned to every two sectors. Accordingly, in each cluster, a total of 16 AUN addresses are recorded. From the recorded AUNs, the address location of each sector can be confirmed. The confirmed sector address is referred to as a physical sector number (PSN).
FIG. 2 is a diagram illustrating a structure of a data frame recorded on the high density optical recording medium. Referring to FIG. 2, a method of forming an error correction code (ECC) in a cluster is shown. First, data to be recorded is formed with user data desired to be recorded and user control data (201). A 4-byte error detection code (EDC) is added to the user data, thereby forming a data frame (202). The data frame forms a scramble data frame (203). Each column of the scramble data frame is again rearranged, thereby forming one data block comprised of 304 columns×216 lines (204).
In order to provide an error correction characteristic to the data block, a Reed-Solomon (RS) code is added to the data block, thereby forming a long distance code (LDC) block (205). Then, using an interleaving process to prevent a concentrated occurrence of errors, the LDC block is transformed to form an LDC cluster of 152 columns×496 lines (206).
By using an address unit including 16 AUN values and control information (207) (16 addresses×9 bytes), the user control data forms an access block so that a recording and reproducing apparatus can access data in a corresponding cluster having 24 columns×30 lines (208). In order to provide an error correction characteristic to the access block, an RS code is added to the access block, thereby forming a BIS block having an additional 32 lines of parity (209). Through an interleaving process to prevent a concentrated occurrence of errors, the BIS block is transformed to form a BIS cluster of 3 columns×496 lines (210).
The LDC cluster and the BIS cluster are divided and arranged in order of LDC, BIS, LDC, BIS, LDC, BIS, LDC, thereby forming a 155 byte ECC cluster (211). Each LDC has a 38 byte size, and each BIS has a 1 byte size in the data frame. Finally, synchronization information and the like are added to the formed ECC cluster, and recorded in a predetermined cluster in the data area (212). The resultant frame has a 20 bit frame sync, and alternating pairs of 25 bit data and 1 bit DC control data.
The capacity of recording media having a data structure as illustrated in FIG. 2 is gradually increasing. However, with the increasing capacity of such recording media, a problem arises in how to secure an address area in the data structure in which the addresses can be recorded.